Breaker arm jig



" April 24, 1945. G KELLS 2,374,601

BREAKER ARM JIG Filed April 25, 1943 @I g m /5 6 h F I QMW mum I IGordon Wei] 6 I we MMMM/QM Patented Apr. 24, 1945 UNITED STATES PAT weeBREAKER AR JIG Gordon Kells, Auckland, New Zeala nd Application April23', 1943, Serial No. 484,256 i In New Zealand March 25,1942

6 Claims This invention has been devised with the object of providing ajig for use in the adjustment and maintenance of the contact pointswofthe rocker arms of the contact breakers used in the rocker arm rocksandto each other, shall be effected throughout theentire life oftheassembly. The jig that forms the subject of this invention providesfor the rocker arm being so positioned and held within it that the facesto be renewed or treated may be readily and correctly oper ated upon bytheir subjection to appropriate forming a groove: 9 beneath the neck ofmetal: 6 joining the two parts together, the part of the neck at thebottom of the groove 9- forming a stop face I against which a point ofthe rocker will hear when in one position.

A fulcrum pin H is provided for passing through the holes I and 8 andadapted to be lationship of the face of the fixed point, and the face ofthe heel to the fulcrum upon which the grinding or filing means toautomatically obtain the proper relative adjustment withthe fulcrum ofthe rocker arm. 1

The inventionwill be described with the aid of the accompanying drawing,wherein: Figure 1 is a perspective view of the jig.

Figure 2 is a side view. Figure 3 is a cross section.

Figure 4 is a cross section with a rocker arm in position for settin upone part, and

Figure 5 is a similar view showing the position passed through thefulcrum boss of a rocker and so fasten-the rocker arniwithin. the slot;

Inl 'igure 4 a rocker arm it has been placed in one position in the slotand held by the pin H being passed through the hole I and boss of therocker, so that the platinum point I3 is held against the face Hi,whilethe @composition heel M is dis-posed to the rounded surfacing plane4 so that this heel can be finished, asby' grinding or filing in.accordance with the face of the plane inorder to renew its surface, the

relationship of .the hole "I, the face I10, and

rounded plane being to ensure the correct angue lar relationship of theheel to the point. 7

In Figure 5, the rockerarm is insertedinthe slot of the block with itsplatinum point l3 lying in the slot so that the. point is disposed tothe surface 2, thus enabling the point to be filed or rubbed by anoilstone in order to reset the point.

The said block faces and the form of the slot and its position inrelation to the faces, as well of the rocker arm whe setting up anotherpart.

Referring to the drawing, the jig is formed of a solid metal block I of.suitable length and of a cross sectional shape providing planar surfaces2 and 3 extending longitudinally througherated upon.

out the length of the blockfand with a rounded or arcuateface 4 onitsperimete r formingfim ishing-element-guiding surfaces, all enclosedwithin a circle so that the block can be cut from asection of roundedbar steel.

The block is formed with a slot 5 extending transversely inwardly for adistance midway of its length sufficient to bisect the planarfaces andalso the rounded face 4, leaving asection of metal 6 to connect the twoparts of the block.

as the positions of the pin receiving holes. passing across the slot,may be varied in a number of ways to suit the type of rocker arm to beop- In all instances, however, the same principles of formationof thejig forming block are carried out. i

I claim: i

1. A jig for positioning and holding rocker arms having contacts whichare spaced from and at an angle to each other so that the contacts lieat a given position with respect toa given portion of the jig comprisinga block having a plurality of finishingwlement-guiding. surfacesextending at an angle to each other and a transverserocker-arm-receiving slot intersectlationship to the other point of therocker arm.

ENT OF E 4 2. A jig for positioning and holding rocker arms havingplanar and arcuate contacts which are spaced from and at an angle toeach other so that the contacts lie at a given position with respect toa given portion of the jig comprising a block having planar and arcuatefinishing-element-guiding surfaces and a transverse rockerarm-receivingslot intersecting said surfaces, said block also having holes extendingnormal to said slot to receive affulcrum pin, the relative positions ofsaid faces to one another and to the holes being such that when a rockerarm is held in said slot by a pin inserted in a selected one of saidholes, coaxial with the fulcrum point of the rocker arm, the rocker armwill be so positioned that one of said contact points is disposed to oneof said finishing-element-guiding surfaces and in correct angularrelationship to the other point of the rocker arm.

3. A jig as set forth in claim 2 in which'the planar face is parallelwith a face at the bottom of the slot.

4. A jig as set forth in claim 2 in which the arcuatefinishing-element-guiding surface extends from each side of the slot sothat the arcuate contact of the rocker-arm may align with such arcuatesurface, and in which a stop surface for engagement by the planarcontact is formed be low the neck portion joining the two portions ofthe block formed by the transverse slot.

5. A jig for positioning and holding rocker arms having contacts whichare spaced from and at an angle to each other so that the contacts lieat a given position with respect to a given portionof the jig comprisinga block having a plurality of- ,finishing-element-guiding surfacesextending at an angle to each other and a stop surface, said block alsohaving a rocker-arm receiving slot intersecting thefinishing-elementguiding surfaces and a hole extending normal to saidslot to receive a fulcrum pin, the relative positions of said surfacesto each other and to the hole being such that when a rocker-arm is Iheld in said slot by a pin coaxial with the fulcrum point of the rockerarm inserted in said hole, with one of said contacts engaging the stopsurface, the rocker arm will be so positioned that the other contactpoint is disposed to the arcuate finishing-element-guiding surface incorrect angular relationship to the first mentioned contact point.

6. A jig for positioning and holding rocker arms having planar andarcuate contacts which are spaced from and at an angle to each other sothat the contacts lie at a given position with respect to a givenportion of the jig comprising a block having an arcuatefinishing-element-guiding surface and a planar stop surface, said blockalso having a rocker-arm receiving slot intersecting thefinishing-element-guiding surface and a hole extending normal to saidslot to receive a fulcrum pin, the relative positions of said surfacesto each other and to the hole being such that when a rocker arm is heldn said slot y a pin coaxial with the fulcrum point of the rocker armbeing received within said hole with the planar contact engaging theplanar stop surface, the rocker arm will be so positioned that thearcuate contact point is disposed to the arcu atefinishing-element-guiding surface in correct angular relation to theplanar contact.

GORDON KELLS.

